High-frequency transformer construction



Dec. 26, 1950 1. GUTHMAN 2,535,203

HIGH-FREQUENCY TRANSFORMER CONSTRUCTION Filed'April e, 1949 INVENTOR Eowm 1. GU'THMAN ATTORNEY 5+ QMJLKM I Patented Dec. 26, 1950 HlGH-FREQUENCY TRANSFORMER CONSTRUCTION Edwin I. Guthman, Chicago, Ill., assignor to Ed- 7 win I. Guthman & 00., Inc., Chicago, Ill., a corporation of Illinois Application April 6, 1949, Serial No. 85,765

1 01am. (or. 171-242) This invention relates to an electrical apparatus and particularly to a high frequency electrical transformer or the like. The invention is particularly useful for use in the intermediate frequency portion of a radio receiver but may have other applications as in discriminato circuits for frequency modulation receivers.

The invention in general comprises a transformer construction wherein ready and convenient assembly'of parts may be obtained, the construction having the advantage of desirable operating characteristics and economy of material as well as convenience of assembly. Other advantages will occur to those skilled in the art in connection with the description.

The invention will now be described in connection with the drawings wherein Figure 1 shows a sectional elevation for the device embodying the present invention. Figure 2 is a sectional elevation on line 2-2 of Figure 1. Figure 3 is a sectional elevation on line 33 of Figure 2. Figure 4 is a transverse section on line 4--4 of Figure 1. Figures 5 and 6 are details.

Referring now to the drawing, elongated insulating tube I has wound thereon windings l l and I2. These windings have a suitable number of turns of suitable wire for the purpose desired. Disposed upon tube ID are end plates i and I6. These plates are of similar construction and as shown in Figure 6 may have a generally rectangular outline with clipped corners l8. Each plate is provided with centrally disposed aperture l9 and two sides have semicircular indentations 20 and 2| respectively on opposite sides thereof. The plates have punched therethrough apertures 24 to 29 inclusive. These apertures are preferably disposed symmetrically with respect to the center of the plate and are elongated as shown.

Plates [5 and i6 are properly oriented so that apertures and slots are alinged along the length of the device. Cooperating with each pair of aligned apertures is elongated spring member 32. It is understood that tube' and plates [5 and [6 are of insulating material while springs 32 are preferably of tinned copper.

Each device has a number of springs and since all are the same, only one will be described in detail. Thus referring to Figure 5, spring 32 has bent ends 33 and 34 and spring portions 35 and 36. Portions 35 and 36 are each shaped to provide inbent portion 38, the inbending being with reference to main spring portion 32. The various spring members are arranged so that the ends are threaded through the corresponding apertures in the end plates. Each spring wire is so disposed that portion 32 in each case will generally be at about the same distance from tube Hi. This is accomplished not only by the proper orientation of apertures 24 to 29 inclusive but also by exercising care as to the orientation of a particular spring in a particular pair of apertures. portions 35 and 36 of each spring will be spaced about the same distance from the nearest portion of another spring. Various connections from the windings to the spring wires may be made as shown, the ends of the windings being soldered to desired wires. It is clear that the tendency of a spring portion to open will maintain the spring wires locked in the end plates.

Extending inwardly into the ends of the tube In are bolts 42 and 43 carrying magnetic slugs or cores 44 and 45 respectively. These cores may be of powdered iron or other metal customary in this art and may be shaped to any desired contour. Cooperating with bolts 42 and 43 are metal end caps 41 and 48. These caps are shaped to fit over the end of a tube and are adapted to hug the end portion of the tube to maintain the same tightly in position.

Covering the device is metal can 50 having one end open. Can 50 has closed end portion 5| suitably apertured for accommodating one of the end caps, in this case cap 41. Can 50 which is preferably rectangular in outline and dimensioned to accommodate end plates l5 and I6 is provided with bolts 53 and 54 attached to the free end of the can at opposite sides thereof. Semi-circular slots 20 and 2| in the end plates are positioned to clear these bolts so that when the device is inserted into the can, a snug fit may be assured. Ground clip 56 is preferably attached to one of the bolts and is long enough so that it may be bent over to reach and be soldered to the adjacent metal end cap 48 in this instance.

As seen in Figure 4, it is possible to so dimension the various parts that wires 32 may be spaced about the same distance from the windings and from the nearest portion of the enclosing can. While some variations in spacing are inevitable, the amount of separation between the wires, windings and. grounded can is such that the differences are small in comparison to the distances themselves.

It will thus be possible to provide a compact structure having desirable spacing of the various parts from each other. Thus the capacitance to ground of the various portions may be made about Thus it will be found that short curved equal. Furthermore, the protruding spring loops from adjacent plate It, these loops being outside the can, are readily available for connection to outside circuits. The construction may be readily assembled and handled with ease.

What is claimed is:

A transformer or the like for high frequencies comprising an insulating tube, windings disposed upon said tube, insulating plates at the ends of said tube, said plates havin aligned apertures, conductors having springloops, there being one conductor threaded through a pair of aligned apertures in the plates with. the springs loops disposed in said apertures, saidspringloops.

having hooked portions for lockin the conductors in the insulating plates connections from said windings to said conductors, a metal shield-'- ing can disposed over said insulating tube and insulating plates, andxmeans for retaining said tube and plates Within said can, said spring loops extendin out of said can at the end thereof'for establishing circuit connections, said apertures being arranged in said plates so that the conductors are disposed generally symmetrically around the insulating tube and said shielding can being disposed generally symmetrically with respect to said tube whereby substantially equidistant spacingof said conductors from said windings and from the walls of the:shielding can is secured.

EDWIN I. GUTHMAN.

REFERENCES CITED The following references are of record in the file of this. patent:

UNITED, STATES PATENTS Number .Name Date 2,180,413 Harvey Nov. 21, 1939 2,346,584 Jacob Apr. 11, 1944 2,392,701 Sanders Jan. 8, 1946 2,448,190 Olesky Aug. 31, 1948 2,464,218 Vita et al. Mar. 15; I949 

